Contact terminal for an electrical conductor member



Allg- 17, 1965 G. w. DEAN 3,201,744

CONTACT TERMINAL FOR AN ELECTRICAL CONDUCTOR MEMBERl Filed Feb. l5, 19613 Sheets-Sheet l INVEDJ TOR.

Goeoofv W DEA/v Bmfw/ rroe/VEYS.

Aug- 17, 1965 G. w. Dx-:AN 3,201,744

CONTACT TERMINAL FOR AN ELECTRICAL CONDUCTOR MEMBER Filed Feb. l5, 19615 Sheets-Sheet 2 -FI/Go INVENTOR.

Goeoo/v W DEAN rroQA/Eys.

G. w. DEAN 3,201,744

CONTACT TERMINAL FOR AN ELECTRICAL CONDUCTOR MEMBER Aug. 17, 1965 5Sheets-Sheet 3 Filed Feb. l5, 1961 INVENTOR. GOQOo/V W DEH/V Bm W'Tra'QA/EYS United States Patent EN'IA'CT TERMINAL EUR AN ELECTRICALCGNDUQTGR MEMBER Gordon W. Dean, Alhambra, Calif., assigner, by mesmeassignments, to international Telephone wd Telegraph Corporation, NewYork, NX., a corporation ot Maryland Filed Feb. l5, 1961, Ser. No.3953 oQlaims. (Cl. 339-97) This invention relates to contact terminals forelectrical conductor members and more particularly to a contact terminalhaving bifurcated parts adapted to grip a strip cable, printed circuitboard, or other electrical conductor member.

The contact terminal of this invention comprises a member of conductingmaterial having front and rear ends wherein the member has a forwardcontacting portion which is adapted to mate with another terminal, and apair of gripping arms or tongs extending rearwardly from the contactingforward portion which are adapted to clamp upon opposite surfaces of aconductor member.

It is an object of this invention t-o provide a Contact terminal whichmay be adapted to grip and complete a contact with various types ofelectrical conductor members and the terminal is especially suitable inconjunction with a conductor member having a generally flat surface,such, for example, as a strip cable or a printed circuit board.

Another object of this invention is to provide a Contact terminalmatable with another contact terminal forming an electrical connector,wherein the electrical conductor members which are engaged by therespective contact terminals may be of Idifferent types as for example aprinted circuit board and an insulated cable.

A further and more speciilc object of this invention is to provide acontactterminal having a pair of gripping arms which are provided withteeth and notches and are adapted to be closed upon an insulatedconductor whereby the teeth will slice through the insulation of theconductor and complete a connection between the conductor and theconta-ct terminal.

Another object of this invention is to provide a contact terminal havinga pair of initially diverging gripping arms which are provided withlocking means to clamp the arms together when converged into connectionrelationship upon an electrical conductor member.

A further object of this invention is to provide in one form thereof acontact terminal wherein the gripping arms embody one or more lockingfingers which are engageable in holes or sockets formed in a printedcircuit board.

Further objects and advantages of the invention will appear from aconsideration of the description which folows wherein the details ofconstruction of embodiments thereof are `described with reference to theaccompanying drawings in which:

FIGURE l is a side elevational view of one form of the contact terminal(pin type) in open position with a strip cable in posit-ion to beclamped;

FIGURE 2 is a side elevational view of the same contact terminal clampedupon ithe strip cable;

FIGURE 3 is a perspective view of an electrical plug comprising aplurality of the novel contact terminals mounted within an insulationhousing;

FIGURE 4 is a cross-sectional view taken on line tllt of FIGURE 3;

FIGURE 5 is an enlarged fragmentary side elevational View of theterminal as illustrated in FIGURE 2 but more clearly showing theengagement of the teeth with the strip cable;

FIGURE 6 is a side elevational View of the Contact terminal illustratinga socket cont-act instead of pin;

nljlli Patented Aug. I7, 1965 FIGURE 7 is a side elevational view of theContact terminal illustrating a modified pin contact portion adapted tobe received in the socket portion of the embodiment shown in FIGURE 6;

FIGURE 8 is a side elevational view of the contact terminal illustratinglocking dogs for retaining the respective arms in parallel closedrelationship;

FIGURE 9 is a perspective view partially in section of contact terminalsof the types illustrated in FIGURE 2 coupled within a socket adaptor toeffect .an electrical connection between a strip cable and a printedcircuit board; and

FIGURE l0 is a cross-sectional view taken on line lll-It) of FIGURE 9.

Illustrated in FIGURES 1 through 8 of the drawings a-re contactterminals generally designated Ztl all of which are adapted to grip aconductor strip or ribbon 21 of an electrical strip cable 22.

The strip cable 22 is formed in the usual manner of a plurality of thegenerally ilat ilexible conductor strips 2l spaced one from the other ina generally parallel relationship. The conductor strips 21 are encasedwithin a strip or tape of flexible insulation material 23.

The -contact terminals Ztl preferably are formed of a fairly hard,durable, conductive material, as for example beryllium copper orphosphor bronze. It should be susceptible to taking a set underapplication of pressure. In width a terminal corresponds generally withthe width of a conductor 21 and is formed with a rounded forwardcon-tact section 24, a rear cable gripping section 25, and a reducedintermediate neck section 26 joining the forward section 24 and rearsection 25. A pair of initially divergent elongated jaws or clampingarms 27 and 2S are ernbodied as parts of the rear section 25, havinginner edge surfaces 3l and 32 and ends 33 and 3d.

On inner edge surface 3l of jaw 27 are formed a plurality of spacedapart pointed teeth 35 projecting from the surface 3l, and a pluralityof spaced apart notches 36 positioned between the teeth 35. Each tooth3S and adjacent notch 36 are partially dened by a common wall 37 whichis generally perpendicular to the inner surface 3l. In my preferredembodiment I illustrate four such alternating teeth and notches.However, a lesser or greater number may be used to achieve the sameresult.

The lower jaw 23 on its inner surface 32 is provided with a Vpluralityof similarly spaced apart pointed teeth 3S projecting toward the upperjaw 27 from the surface 32, and a plurality of spaced apart notches 39.There are common walls 4) forming one side of each tooth 38 and notch 39comparable and complementary to the walls 37 of the upper jaw 27. Thepositioning of the teeth 38 and notches 39 on the surface 32 is suchthat a notch 39 is aligned under a tooth 35 on the jaw 27 and the notch36 is aligned and adapted to receive a tooth 3S on the lower jaw, whenthe two jaws are closed generally parallel to each other as shown inFIGURES 2 and 5.

The longitudinal relative spacing of the teeth, notches and walls of thetwo jaws is Such that when the jaws are closed and consequently therespective teeth 3S and 3S enter into the notches 36 and 39, the spacebetween the respective walls 37 and ttl will be graduated in width fromthe teeth closest to the neck 26 toward the teeth nearest ends 33 and34. The reason for `the spacing will be subsequently explained.

In order to complete a connection between a terminal 2Q and a conductorstrip 2l of the strip cable 22, an end 4S of the cable is insertedbetween the jaws 27 and Z8 so that the end is in close proximity to thepoint where the jaws converge, the conductor strip 2l is parallel to andaligned between the jaws 27 and 23. In this position the two jaws 27 and28 are pressed together in any convenient manner so that the pointedteeth 35 and 3S engage the insulation 23 on both sides of the conductorstrip 21.

As the jaws are brought together the teeth 35 and 33 bite into theinsulation on each side of the conductor and slice and peel theinsulation away, thus baring the conductor 21 so that a connection ismade between the wall 37 with one side of the conductor 21 and wall 40with the other side of said conductor, as illustrated in FIGURE 5. Asthe insulation is peeled by the biting action it is forced into andpacks inthe respective notches 36 and 39.

In the manufacture of strip cable 22 there is generally a manufacturingtolerance of 1.6002 in the thickness of each conductor strip 21. Inorder to assure adequate connections between the terminal teeth wallsand the conductor strip, because of this tolerance, it has been foundthat best contact results are achieved if the spacing between the middleset of teeth is set for the exact dimension of the thickness of theyconductor strip 21 as specified by the manufacturer, while the spacingbetween the teeth nearest the neck 26 is set for the minimum toleranceor slightly less than the specified thickness of the conductor so thatteeth will bite into the conductor, and possibly rupture it as at 45a asshown in FIGURE 5. The spacing of the teeth nearest the ends 33 and 34of the jaws is set for the maximum tolerance or slightly wider than thespecified thickness of the conductor strip 21.

In this way it will be seen that the fiexible conductor 21 will beconnectively engaged by at least one of the teeth depending on itsthickness as the jaws 27 and 28 are closed upon each other. Further,with the utilization of a series of teeth having graduated spacing, theconductor 21 will always be retained within the contact terminal 2G, andshould the teeth adjacent the neck 26 rupture the conductor strip 21 oneor more of the other teeth will retain the conductor within the jaws.

An assembly in the nature of a plug 46 retaining and mounting a seriesof terminals 20 which are severally secured to conductors 21 of stripcable 22, is illustrated in FIGURES 3 and 4. This plug comprises ahousing block 45a which includes an upper section 47 and a similar lowersection 48, formed of insulation material. The sections 47 and 48 areeach provided with a series of elongated laterally spaced parallel slots49 which extend through the sections from the front surface to the rearsurface 51 of the housing. The slots 49 are of a size and configurationto snugly accommodate the major portions of the contact terminals 2t)and are spaced from each other to correspond to the spacing of theconductors 21 within the strip cable 22. This configuration incorporatessimilar flanges 52 which extend toward each other within the slots.These fianges engage walls 53 and 54 defining upper and lower recessesformed by the reduced neck 26 of the terminals 2d.

The terminals 20, after being clamped on the conductors 21, are insertedin the slots 49,015 the lower section 4S, and the upper section issuperimposed over the lower section with the sections 47 and 48 beingheld together in any conventional manner, as for example by screws 55.

When the plug is assembled at the end of the strip cable as described,the rounded front pin contact sections 24 of the terminals 23 projectbeyond the front surface Si? of the housing and are thus adapted to matewith sockets of a receptacle (not shown) in order to complete aconnector comprlsing plug and receptacle.

It is found desirable to incorporate ledges 57 and 58 on the top surface59 and bottom surface 63 of the respective sections 47 and 43 to act asstop means which engage a suitable complementary stop element (notshown) on a receptacle housing or adaptor such as on a panel board orthe like.

Referring to FIGURE 8, there is shown there a contact terminal generallyidentical to the form shown in FIGURES 1 5, but with the added featureof latching of insulation material.

means on the jaws or arms 27 and 2S to lock the respective jaws togetherand consequently upon the conductor 21 when the jaws are in closedparallel relationship. The latching means comprises a pair of resilientpointed dog latch members 65 and 66 extending from the respective innersurfaces 31 and 32 toward each other and longitudinally offset one fromthe other so that as the jaws 27' and 28' are closed together theconductor strip 21 and insulation 23 is pierced and broken by the pointsof the latches 65 and 66.

There is provided a space 7u in jaw 27 in front of the latch member 66and another space 71 in jaw 28' at the rear of latch member 65. Thesespaces 70 and 71 will allow the members 65 and 55 to give as theycontact each other along biased camming surfaces 67 and 68 and snap locktogether at offset complementary abutting faces 69.

FIGURES 6 and 7 illustrate contact terminals 20 wherein the contactportion in FIGURE 6 is a form of socket adapted to mate with a pin 76 ofFIGURE 7. The socket 7S is of a generally prong type, having upper andlower resilient spring contact arms 77 and '78 which extend forward fromthe rear portion 25' and define an opening 79. The pin portion 76 shownin FiGURE 7 includes a pair of generally parallel resilient springfingers St) and 81 adapted to slide within the arms 77 and '78.

Protrusions 79a are formed on the arms 77 and .78 to provide arestricted opening for entrance of the pin 76 and consequently a goedfrictional contact.

FIGURE 9 illustrates a form of coupling receptacle 110 which is adaptedto connect a strip cable 22 with a printed circuit board 85 or connectany other conductor elements both provided with the terminals 2t?. Thecoupling utilizes a monoblock construction formed It includes a panelwall 111 and extending generally perpendicular from one side of saidwall an upper and lower shelf 112 and 113 which are parallel with andspaced from each other. The wall 111 and shelves 112 and 113 define anopening 114. On the other side of said wall 111 are similarly spacedshelves 115 and 116 defining a second opening 117. The wall 111 isprovided with a plurality of generally dumbbell shaped openings 11S eachof which is aligned with an opening 114 and an opening 117 communicatestherewith.

A double ended snap-in socket 119 generally circular in cross-section isinserted in opening 118 so that gripping portions 1191; of flaredfingers 120 extend into the opposite openings 114 and 117.

In order to complete a connection between the conductors of a printedcircuit board and strip cable, a terminal and circuit board assembly,generally designated 20', is inserted in the opening 117 so that the pinportion 24 and a part of the jaws are engaged by and retained in thefingers 120. Also the pin portion 20 and forward reduced portion 121 ofplug 46 is inserted into opening 114 where the pin portion 20 will beengaged by the fingers in the gripping portion 11911 of the socket 119.The ledges 57 rearwardly terminating the reduced portion 121 will act asforward stops and abut the ends 122 and 123 of the respective shelves112 and 113.

While specific embodiments of the present invention have been disclosedin the foregonig description, it will be understood that variousmodifications within the spirit of the invention may occur to thoseskilled in the art. Therefore, it is intended that no limitation beimposed on the invention except as defined by the scope of the appendedclaims.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A contact terminal and conductor member attached thereto and saidcontact terminal adapted to mate with another terminal, said combinationcomprising: a member of conductive material having front and rear ends,said member having a forward contacting portion adapted to mate withanother terminal, a pair of clamping arms extending rearwardly from saidcontacting portion in generally parallel relationship to each other,said arms having opposed inner surfaces, and a conductor member heldbetween said clamping arms, means provided on said inner surfaces forretaining said conductor member between said inner surfaces againstlongitudinal relative displacement, Wherein said means includes a toothprojecting from each of said respective inner surfaces andlongitudinally spaced from each other, and wherein each of said teethembodies an edge wall extending from the point of the tooth back intothe clamping arm and the arm is cut out adjacent the edge wall toprovide a notch, which notch accommodates a tooth projecting from theopposite arm, the adjacent edge walls lying in generally parallelproximity, and the conductor member is frictionally engaged between andby said proximate walls.

2. A contact terminal and conductor member combination as defined inclaim 1 wherein each inner surface is provided with a plurality oflongitudinally spaced teeth and notches.

3. A contact terminal and conductor member combination as dened in claim2 wherein the longitudinal spacing beetwcen the edge walls on thegripping arms is varied.

4. An electrical contact terminal and insulated conductor strip membersecured thereto and said contact terminal adapted to mate with anothercontact terminal,

said combination comprising: a member of conductive material havingfront and rear ends, said member having a forward contacting portionadapted to mate with another terminal, a pair of clamping arms extendingrearwardly from said contacting portion in generally parallelrelationship to each other, said arms having opposed inner surfaces,said conductor member being a tape of conductive material covered by aribbon coating of nsulation, an end portion of said conductor memberbeing inserted between the inner surfaces of said clamping arms withsaid conductive tape extending parallel with and in the plane of saidclamping arms and bite means on the inner surfaces of said armspenetrating said insulation from opposite sides of said conductive tapeand which the conductive tape is held with said bite means said bitemeans meshing to define a zig-zag space within in engagement with theconductive material of the conductor member.

5. An electrical contact terminal and insulator conductor strip memberas defined in claim 4 wherein the bite means penetrating said insulationinclude opposed teeth on the respective inner surfaces.

6. A combination as defined in claim 5 wherein relief notches are formedadjacent the teeth to receive insulation removed from the conductivetape.

References Cited hy the Examiner UNITED STATES PATENTS 1,200,825 10/ 16Fenety 339-97 X 1,630,936 5/27 Godley 339-241 X 1,956,019 4/34 Gilbert339-196 X 2,012,627 8/ 35 Gilbert 339-97 2,175,759 10/ 39 Olson.

2,309,311 1/43 Grohsgal 339-97 2,396,725 3/46 Thomas 339-198 2,622,12112/ 52 Pedersen 339-196 2,658,184 11/53 Greenbaum 339-99 2,701,346 2/55Powell 339-17 2,721,981 10/55 Modrey 339-198 2,929,043 3/ 60 Phillips339-99 2,959,766 11/60 Jacobsen 339-276 X 2,962,692 1 1/ 60 White.

2,965,699 12/60 Bollmeier 339-98 X 2,993,188 7/61 Anderson 339-172,999,997 9/61 Tuchel 339-17 3,021,500 2/62 Pohl 339-96 X FOREIGNPATENTS 988,321 4/51 France. 1,097,511 1/61 Germany.

209,306 1/24 Great Britain.

JOSEPH D. SEERS, Primary Examiner.

1. A CONTACT TERMINAL AND CONDUCTOR MEMBER ATTACHED THERETO AND SAIDCONTACT TERMINAL ADAPTED TO MATE WITH ANOTHER TERMINAL, SAID COMBINATIONCOMPRISING: A MEMBER OF CONDUCTIVE MATERIAL HAVING FRONT AND REAR ENDS,SAID MEMBER HAVING A FORWARD CONTACTING PORTION ADAPTED TO MATE WITHANOTHER TERMINAL, A PAIR OF CLAMPING ARMS EXTENDING REARWARDLY FROM SAIDCONTACTING PORTION IN GENERALLY PRALLEL RELATIONSHIP TO EACH OTHER, SAIDARMS HAVING OPPOSED INNER SURFACES, AND A CONDUCTOR MEMBER HELD BETWEENSAID CLAMPING ARMS, MEANS PROVIDED ON SAID INNER SURFACES FOR RETAININGSAID CONDUCTOR MEMBER BETWEEN SAID INNER SURFACES AGAINST LONGITUDINALRELATIVE DISPLACEMENT, WHEREIN SAID MEANS INCLUDES A TOOTH PROJECTINGFROM EACH OF SAID RESPECTIVE INNER SURFACES AND LONGITUDINALLY SPACEDFROM EACH OTHER, AND WHEREIN EACH OF SAID TEETH EMBODIES AN EDGE WALLEXTENDING FROM THE POINT OF THE TOOTH BACK INTO THE CLAMPING ARM AND THEARM IS CUT OUT ADJACENT THE EDGE WALL TO PROVIDE A NOTCH, WHICH NOTCHACCOMMODATES A TOOTH PROJECTING FROM THE OPPOSITE ARM, THE ADJACENT EDGEWALLS LYING IN GENERALLY PARALLEL PROXIMITY, AND THE CONDUCTOR MEMBER ISFRICTIONALLY ENGAGED BETWEEN AND BY SAID PROXIMATE WALLS.